Three position snap switch utilizing interference blade means



July 19, 1966 R. E. M VICKER 3 3,

THREE POSITION SNAP SWITCH UTILIZING INTERFERENCE BLADE MEANS 3 5'Sheets-sheet '1 Filed March 4. 1965 RICHARD E. M VICKER ATTOR July 19,1966 CWCK R 3,261,937

THREE POSITION SNAP SWITCH UTILIZING INTERFERENCE BLADE MEANS Flt B. 5

INVENTOR. RICHARD E. MVI CKER ATTORNEY July 19, 1966 dv g R I i3,261,937

THREE POSITION SNAP SWITCH UTILIZING INTERFERENCE BLADE MEANS FiledMarch 4, 1965 5 Sheefc-Sheef 3 7 43 L r\ 3 3|3 3 n k\\\\ 297// i 3 I 9.3 26 E 4 w/ I6 v 46 J l2 INVENTOR. RICHARD E. m wcxen ATTORNEY UnitedStates Patent 3,261,937 THREE POSITION SNAP SWITCH UTILIZINGINTERFERENCE BLADE MEANS Richard E. McVicker, Indianapolis, Ind,assignor to P. R. Mallory & Co., Inc., Indianapolis, Ind., a corporationof Delaware Filed Mar. 4, 1965, Ser. No. 437,234 8 Claims. (Cl. 200-457)The present invention relates to snap action mechanisms and moreparticularly relates to a double throw snap action mechanism having aneutral or off position.

Snap action mechanisms have found great utility in recent years sincethey are relatively simple and economically manufactured and since theyare operable to actuate the mechanims with which they are associatedwith a positive stroke of the snap blade even though the force whichacts to actuate the mechanism is applied very slowly. More particularlysuch snap action mechanisms have found particular utility in theelectrical field in the form of double throw snap action switches sincethe quick snapping action of the snap blade associated with themechanism is effective to substantially eliminate arcing between twoadjacent contacts.

Heretofore, however, such snap action mechanisms have been simply of thesingle or double throw type having no provision for maintainin the snapblade associated with the mechanism in an intermediate position. A fewdouble throw mechanisms have been provided; however, while they have aneutral position, they do not provide snap action in both directions.They also require separate actuating means for the top and bottomstroke. Those skilled in the art of designing and using snap actionmechanisms and particularly those acquainted with the adaptability ofthe same to the electric field will recognize the desirability ofproviding a snap action mechanism having a neutral or off position sothat in essence, a triple throw switch having positive snap action inall directions is provided.

It is therefore an object of the present invention to provide a snapaction mechanism in which the snap blade associated therewith may becontrollably moved to any of three separate positions.

It is an object of the present invention to provide a snap action switchof the type described which may be readily and economicallymanufactured.

It is an object of the present invention to provide a snap actionmechanism wherein the snap blade associated therewith may be moved toany of three separate positions as desired and wherein movement of thesnap blade to these respective positions is effected as a function ofthe degree of movement of the usual actuator lever associated therewith.

The present invention, in another of its aspects, relates to novelfeatures of the instrumentalities described herein for teaching theprincipal object of the invention and to the novel principles employedin the instrumentalities whether or not these features and principlesmay be used in the said object and/ or in the said field.

Other objects of the invention and the nature thereof will becomeapparent from the following description considered in conjunction withthe accompanying drawings and wherein like reference numbers describeelements of similar function therein and wherein the scope of theinvention is determined rather from the dependent claims.

For illustrative purposes, the invention will be described inconjunction with the accompanying drawings in which:

FIGURE 1 is an exploded view of a snap action mechanism constructed inaccordance with the principles of the present invention;

FIGURE 2 is a sectional view of the snap action mechanism showing thesnap blade or movable contact in a first position;

FIGURE 3 is a sectional view of the snap action mechanism showing thesnap blade or movable contact in an intermediate position;

FIGURE 4 is a sectional view of the snap action mechanism showing thesnap blade or movable contact in a third position; and

FIGURE 5 is a sectional view of the snap mechanism showing the snapblade or movable contact in a first position and super-imposed neutraland third positions.

Generally speaking, the present invention relates to a switch mechanismwherein the snap blade or movable contact associated with the mechanismis movable to any one of three selected positions as desired.

In the embodiment of the invention illustrated in FIG- URES 1-5, a snapaction mechanism is shown by way of example, and not by way oflimitation, being adapted for use as a double throw electrical switch.Switch 10 has movable blade 11 cantilevered in step 13 at a first end ofhousing 12 and positioned therein by post 14. A cantilevered centerresilient blade 11 is located within resilient movable blade 15 and isfree to move in a vertical plane therein. Top portion 16' of camfollower 16 is disposed in aperture 16" of blade 11 and aperture 16 ofactuating block 17.

Block 17 and follower 16 are molded from a suitable insulating materialsuch as nylon and are heat staked after being assembled. Actuating block17 has fingers 18 and 18' thereon which provide an interference withblade 15 in conjunction with fingers 19 and 19' (not shown) on camfollower 16, thereby providing means for bowing blade 15 in an upward ordownward motion respectively. Retaining means 20 and 21 prevent verticalmovement of end portion 15 of blade 15. Portion 15' is the controllableinterfering portion which lays in the path of tongue 35 as arm 32 isactuated.

Disposed at a second end of housing 12 is cantilevered arm 22 which ispositioned by post 23 in step 24. Arm 22 ends in a spade terminal 26 ona first end and has a stationary contact adjacent the second end on thetop surface thereof. Insulating pivot block 27 separates arm 22 fromupper contact arm 28. Cantilevered arm 28 is held in place by post 23and by step 29 of block 27. Upper stationary contact 30 is afiixed tothe lower side of arm 28 adjacent a first end. The second end of arm 28terminates in spade terminal 31.

Block 27 has V-notch 32 for receiving a first end of movable contact arm33. Arm 33 is held in notch 32 by spring tension exerted from bow spring34 which interfits with tongue 35 at a second end of arm 33 and tongue36 of blade 11. Arm 33 has upper movable contact 37 on a top surface andbottom movable contact 38 (FIGS. 2, 3, 4 and 5) on a bottom surface.

Coil spring 39 straddles boss 40 (FIGS. 2, 3, 4 and 5) of tophousing-member 41 and is seated on cap 42. Cap 42 interfits with groove43 of block 17. Coil spring 39 serves to return cam follower 16 in adownward direction. After assembly top housing member 41 and bottomhousing member 12 are heat staked by top portions 43 and 44 of posts 14and 23 respectively. Bottom housing member 12 has snap-in posts 45 and46 respectively for rapid assembly into a mounting member for switch 10.The snap-in feature eliminates riveting or screwing switch 10 into itsmounting means.

In the operation of switch 10, as cam follower 16 is actuated by cam 47,follower 16 moves in an upward direction until the end portion 36 ofblade 11 is higher than tongue 35 of arm 33 which has been at restagainst top contact 30 by virtue of contact 37 as shown in FIG- URE 2.When portion 36 of blade 11 is higher than tongue 35, the over centerC-spring 34 is subject to maximum stress and the spring reverses andsnaps contact arm 33 in a downward direction, there-by breaking contact.As arm 33 continues to move in a downward direction tongue 35 strikesthe interference end of blade 15 and comes to rest at that position asshown in FIGURE 3 thereby creating a neutral or off position. Arm 33will remain in the neutral position until cam follower 16 moves furtherin an upward direction. As follower 16 moves upwardly, fingers 19 and 1Wcome into contact with blade 15 and carry the middle portion of theblade 15 in an upward position, causing blade 15 to bow and therebyshortening the overall length. When blade 15 has reached maximumdisplacement, tongue 35 bypasses end 15' of blade 15 and arm 33 moves ina downward direction from the force of C-spring 34 until contacts 38 andmate thereby providing a second electrical connection as shown in FIGURE4.

The aforementioned motion is duplicated in reverse as follower 16 isallowed to move in a downward direction as it conforms to the shape ofcam 47, because of the downward force exerted by coil spring 39 as shownin FIGURE 5. As can be seen from FIG. 5, the same members provide twocycles, movement from top to neutral to bottom and movement from bottomto neutral to top.

The present invention provides a positive snap action to and from bothcontacts and a neutral or off position. Thus electrical contact mayinitially be made to both first and second contacts and a neutralposition still be provided.

The present invention as hereinabove described and in its representativeembodiment is merely illustrative and not exhaustive in scope. Sincemany widely differing embodiments of the invention may be made withoutdeparting from the scope thereof, it is intended that all mattercontained in the above description and shown in the accompanying drawingshall be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim:

1. A snap action switch mechanism having first, intermediate and thirdpositions comprising:

(a) a mounting member;

(b) a pair of transversely spaced arms cantilevered to said mountingmember, each of said arms having contacts thereon;

(c) an insulating block separating said arms, said block having a notchtherein for receiving a first end of a contact arm;

((1) said contact arm disposed intermediate said spaced arms;

(e) an actuator blade pivotally mounted on said memher, said actuatorblade having a notch therein for receiving a top portion of a camfollower;

(f) biasing means interconnecting a second end of said contact arm andsaid actuator blade for selectively snapping said contact arm toward oneof said spaced contacts;

g) an interference blade means mounted on said mounting means forproviding a rest position for said movable contact blade, and guidemeans formed on said mounting means for preventing vertical motion atone section of said interference blade and permitting horizontal motionat another section of said interference blade, finger means on said cammeans for actuating said interference blade and said actuator bladethereby allowing said arm to bypass said interference blade;

(h) spring means for urging said actuator blade downwardly;

(i) and a housing member, said housing member being heat staked to saidmounting member.

2. A snap action switch mechanism having first, intermediate and thirdpositions comprising:

(a) a mounting member;

(b) a pair of transversely spaced arms cantilevered to said mountingmember, each of said arms having contacts thereon;

(c) an insulating block separating said arms, said block having a notchtherein for receiving a first end of a contact arm;

(d) said contact arm disposed intermediate said spaced arms;

(e) an actuator blade pivotally mounted on said member, said actuatorblade having a notch therein for receiving a top portion of a camfollower;

(f) biasing means interconnecting a second end of said contact arm andsaid actuator blade for selectively snapping said contact arm toward oneof said spaced contacts;

(g) an interference blade means mounted on said mounting means forproviding a rest position for said movable contact blade, and guidemeans formed on said mounting means for preventing vertical motion atone section of said interference blade and permitting horizontal motionat another section of said interference blade, finger means on said cammeans for actuating said interference blade and said actuator bladethereby allowing said arm to bypass said interference blade;

(h) spring means for urging said actuator blade downwardly;

(i) and a housing.

3. A snap action switch mechanism having first, intermediate and thirdpositions comprising:

(a) amountingmember;

(b) a pair of transversely spaced contact arms affixed to said mountingmember;

(c) an insulating block separating said arms, said block having a notchtherein for receiving a first end of a contact arm;

((1) said contact arm disposed intermediate said spaced arms;

(e)'an actuator blade pivotally mounted on said member, said actuatorblade having a notch therein for receiving a top portion of a camfollower;

(f) biasing means interconnecting a second end of said contact arm andsaid actuator blade for selectively snapping said contact arm toward oneof said spaced contacts;

g) an interference blade means mounted on said mounting means forproviding a rest position for said movable contact blade, and guidemeans formed on said mounting means for preventing vertical motion atone section of said interference blade and permitting horizontal motionat another section of said interference blade, finger means on said cammeans for actuating said interference blade and said actuator bladethereby allowing said arm to bypass said interference blade;

(h) spring means for urging said actuator blade downwardly;

(i) andahousing.

4. A snap action switch mechanism having first, intermediate and thirdpositions comprising:

(a) a mounting member;

(b) a pair of transversely spaced contact arms affixed to said mountingmember;

(0) a movable contact arm disposed intermediate said spaced arms;

(d) an actuator blade pivotally mounted on said member, said actuatorblade having a notch therein for receiving a top portion of a camfollower;

(e) biasing means interconnecting said movable contact arm and saidactuator blade for selectively snapping said contact arm toward one ofsaid spaced contacts;

(f) an interference blade means mounted on said mounting means forproviding a rest position for said movable contact blade, and guidemeans formed on said mounting means for preventing vertical motion atone section of said interference blade and permitting horizontal motionat another section of said interference blade, finger means on said cammeans for actuating said interference blade and said actuator bladethereby allowing said arm to bypass said interference blade;

(g) spring means for urging said actuator blade downwardly;

(h) and a housing member.

5. A snap action switch mechanism comprising:

(a) a mounting member;

(b) a pair of spaced apart contact arms afiixed to said mounting member;

(c) a movable contact arm disposed intermediate said spaced apart arms;

((1) an actuator blade pivotally mounted on said member, a cam followerengaging said actuator blade;

(e) biasing means interconnecting said movable contact arm and saidactuator blade for selectively snapping said contact arm toward one ofsaid spaced con tacts;

(f) an interference blade means mounted on said mounting means forproviding a rest position for said movable contact blade, and guidemeans formed on said mounting means for preventing vertical motion atone section of said interference blade and permitting horizontal motionat another sectiton of said interference blade, finger means on said cammeans for actuating said interference blade and said actuator bladethereby allowing said arm to bypass said interference blade;

(g) spring means for urging said actuator blade downwardly;

(h) and a housing member.

6. A snap action switch comprising: a housing, a plurality of discretecontact arms mounted in said housing, a movable contact arm mounted insaid housing and connected to an actuator means by a bias means,follower means coupled to said actuator means for actuating said movablecontact arm to predetermined positions in a snap action manner, meanssupported by said housing and including an interference portion, saidportion positioned in the path of movement of said movable contact arm,and means coupled to said follower means and responsive to the movementthereof for actuating said portion to thereby allow said movable contactarm to move into engagement with one of said discrete contact arms.

7. A switch mechanism comprising:

(a) ahousing;

(b) a spaced apart contact carrying means retained by said housing;

(c) a movable contact carrying means disposed intermediate said spacedapart contact carrying means;

(d) an actuator means retained by said housing, a follower meansengaging said actuator means, said actuator means displaced by adisplacement of said follower means;

(e) biasing means interconnecting said movable contact carrying meansand said actuator means for displacing said contact carrying meanstoward one of said spaced apart contact carrying means; and

(f) an interference means retained by said housing for providing a restposition for said movable contact carrying means, and guide means onsaid mounting means for substantially preventing vertical motion at onesection of said interference means and permitting horizontal motion atanother section of said interference means, means on said follower meansfor actuating said interference means and said ac tuator means therebyallowing said movable contact carrying means to move from saidintermediate position to an engaged position with said one contactcarrying means.

8. A snap action switch comprising: a housing; a plurality of discretearms retained in said housing in spaced relationship; a movable contactcarrying arm disposed between said spaced apart contact arms; anactuator means having one portion retained by said housing and a secondportion coupled to said movable arm by a biasing means, said biasingmeans for snapping said movable arm toward one of said discrete contactarms; follower means coupled to said actuator means for actuating saidmovable arm to predetermined positions through displacement of saidactuator means and said biasing means; an interference means retained bysaid housing and positioned in the path of movement of said movable arm,said interference means providing a rest position for said movable arm;and means coupled to said follower means and responsive to the movementthereof for actuating said interference means to thereby allow saidmovable arm to move from said rest position to an engaged position withone of said discrete contact arms with a snap action motion.

No references cited.

ROBERT K. SCHAEFER, Primary Examiner.

8. A SNAP ACTION SWITCH COMPRISING: A HOUSING; A PLURALITY OF DISCRETEARMS RETAINED IN SAID HOUSING IN SPACED RELATIONSHIP; A MOVABLE CONTACTCARRYING ARM DISPOSED BETWEEN SAID SPACED APART CONTACT ARMS; ANACTUATOR MEANS HAVING ONE PORTION RETAINED BY SAID HOUSING AND A SECONDPORTION COUPLED TO SAID MOVABLE ARM BY A BIASING MEANS, SAID BIASINGMEANS FOR SNAPPING SAID MOVABLE ARM TOWARD ONE OF SAID DISCRETE CONTACTARMS; FOLLOWER MEANS COUPLED TO SAID ACTUATOR MEANS FOR ACTUATING SAIDMOVABLE ARM TO PREDETERMINED POSITIONS THROUGH DISPLACEMENT OF SAIDACTUATOR MEANS AND SAID BIASING MEANS; AN INTERFERENCE MEANS RETAINED BYSAID HOUSING AND POSITIONED IN THE PATHL OF MOVEMENT OF SAID MOVABLEARM, SAID INTERFERENCE MEANS PROVIDING A REST POSITION FOR SAID MOVABLEARM; AND MEANS COUPLED TO SAID FOLLOWER MEANS AND RESPONSIVE TO THEMOVEMENT THEREOF FOR ACTUATING SAID INTERFERENCE MEANS TO THEREBY ALLOWSAID MOVABLE ARM TO MOVE FROM SAID REST POSITION TO AN ENGAGED POSITIONWITH ONE OF SAID DISCRETE CONTACT ARMS WITH A SNAP ACTION MOTION. CRETECONTACT ARMS WITH A SNAP MOTION.